In the oil and gas business, in the petrochemical industry, in processing plants, and for utility companies and utility providers, for example, often more time and money is spent trying to find leaks than fixing leaks. One of the biggest challenges is trying to find the leaks using conventional methods. Many conventional methods can simply miss a leak and not detect it if the detector is not properly positioned over or downwind of the leak. Also, many conventional methods are very time consuming and labor intensive, which leads to more expense. Hence, there is a great need for a faster, more accurate, and less expensive method of detecting such leaks.
Petroleum products, such as liquid, gas, and liquid/gas forms of hydrocarbon compounds (e.g., fossil fuels), are often transmitted or channeled in pipes. The conventional method of surveying lines for petroleum product leaks or for detecting petroleum product leaks in general is with a flame-pack ionizer detector (also sometimes referred to as a “sniffer” device). Another recently developed system uses an active infrared system (having a transmitting infrared source and a receiving sensor) for detecting petroleum product fumes. However, such systems require that the detector be within the stream or plume of the petroleum product leak. These tests merely detect the presence of petroleum product fumes at or upwind of the detector. They do not provide a visual image of the leak. Also, these prior testing methods require the detector to be in the immediate proximity of the leak, which may be dangerous and/or difficult for the inspector.
Prior infrared systems designed for evaluating rocket fumes, for example, would provide an unfocused and fuzzy image, in which it was difficult to make out background objects. For example, using an infrared camera that images a broad range of infrared wavelengths (e.g., 3-5 microns) typically will not be useful in detecting small leaks. One system uses a variable filter that scans through different bandwidths in an attempt to identify the bandwidth of the strongest intensity (as quantified by the system). The purpose of this system was an attempt to identify the chemical make-up of a rocket exhaust based on the wavelength at which the intensity was greatest for the rocket plume. However, this system is not designed to provide a focused visual image to view the rocket exhaust.
Others have attempted to visualize petroleum product leaks using infrared cameras using a “warm” filter setup and/or an active infrared camera system. A warm filter setup is one in which a filter is used to limit the wavelengths of light that reach the infrared sensor, but the filter is not in a cooled or refrigerated portion of the camera, if the camera even has a refrigerated portion. Such systems have not been able to provide a focused image capable of quickly and easily detecting small leaks, nor being capable of detecting leaks from a distance (e.g., from a helicopter passing over a line). Other systems are active and require a laser beam to be projected through the area under inspection in order to detect the presence of a chemical emanating from a component. However, with such systems, typically the narrow laser beam must cross the flow stream for the leak to be detected. Hence, a leak may be missed if the laser beam does not cross the path of the leak and such systems often are unable to reliably find small leaks. Hence, a need exists for a way to perform a visual inspection to find leaks with reliability and accuracy, while being faster and more cost effective than existing leak survey methods.
The U.S. Environmental Protection Agency (EPA) has proposed rules to allow visual inspections using infrared cameras in performing leak inspection surveys. However, due to the lack of detection abilities and poor performance demonstrated by other prior and current systems, the EPA had not yet implemented such rules. Thus, even the EPA has been waiting for someone to provide a system or way of reliably and accurately detecting leaks of various sizes.